You may have heard of ReFS file system on the Windows forums and other tech tips websites. Read here about the new file system from Microsoft and how it is different from NTFS.
- 1 What Is ReFS? A Brief History:
- 2 Advantages Over NTFS:
- 3 Limitations Of ReFS:
What Is ReFS? A Brief History:
ReFS stands for Resilient File System. It is the latest file system from Microsoft designed to manage large data sets and diverse workloads. The ReFS file system was introduced with Windows Server 2012 as a future successor to the NTFS.
It was primarily designed to overcome the problems that were significant with the NTFS file system and to significantly reduce the integrity issues that are apparent with the NTFS file system. It has built-in handling of hard disk drive failure and capacity to handle very long file names and sizes.
Advantages Over NTFS:
ReFS was introduced in August 2012 along with Windows server 2012. Earlier builds of the ReFS showed it to be just slightly faster than NTFS, and significantly slower in full integrity checking of a disk drive. This was improved over time and the current versions have improved vastly in handling data degradation and HDD failures and redundancy.
The key design advantages of ReFS are:
1. Built-in Resilience For Data And Disk Corruption
A new technology introduced with the new file system was the allocation of write update strategy. New chunks are allocated for every updated transaction and large IO batches are used.
If a file or metadata becomes corrupted for some reason, that data file can be removed without taking the whole drive offline for maintenance purposes. Administrators also font need to periodically check for errors using tools like CHKDSK while using the ReFS file system.
ReFS introduced a data integrity scanner called scrubber that periodically scans the volume for latent corruption and triggers the repair of corrupt data.
2. Improved Reliability
The metadata and file data in ReFS are organized into tables similar to the relational database. The file data properties are limited by 64-bit numbers. As a result:
- Maximum file size: 16 exbibytes
- Maximum directories: 18.4*1018
- Maximum volume size: 35 Petabytes
- Maximum filename length: 255 Unicode Characters
- Maximum path-name length: 32768 Unicode Characters
ReFS also preserves and enforces access control lists (ACLs) for improved reliability as well.
3. Accelerated Virtual Machine Operations
For improving the performance of virtualized workloads, ReFS introduced new functionalities called Block Cloning and Sparse VDL
- Block cloning accelerates copy and paste operations so that the virtual machines checkpoint merge operations can occur without hampering the performance of your system.
- Sparse VDL is a new technology that allows ReFS to zero files (zero fill) very quickly. This, in turn, reduces the time taken to create fixed Virtual Hard Disk Drives down to mere seconds.
4. Performance (Mirror Accelerated Parity)
ReFS introduced new features for performance-sensitive workloads. A special feature is termed as Mirror accelerated parity that was introduced to deliver high performance and storage efficient data saving/
Basically, ReFS divides a volume into 2 logical storage groups. These groups are called
- Performance tier
- Capacity tier
These tiers can have their own drives and resiliency types. Once these tiers are configured, they are used to deliver fast storage for hot data and capacity-efficient storage for cold data.
The performance tier handles all the write functions, and the residual large chunk data is efficiently moved to the Capacity Tier. the effect of data fragmentation characteristic of visualized workload is significantly reduced. Reads also can occur in the Performance tier if all flash drives are being used.
Limitations Of ReFS:
Although ReFS is a new file system type, it does not have some features that are present in the NTFS file system.
1. Not bootable and not supported on removable media
As of June 2019, the ReFS file system formatted drive cannot be used to boot into Windows. This is one of the most significant drawbacks of the ReFS file system.
ReFS is also not supported on removable storage media as of now, so you cannot format your flash drives or external HDD in ReFS file system. These need to be formatted into NTFS only.
2. File-level functionality absent
ReFS does not include file-level compression and encryption, disk quotas and hard links. These were the advantages of NTFS over FAT file system, and not seeing them in ReFS is strange.
However, do note that ReFS supports sparse files, re-parse points, case sensitive file names and Unicode in file names.
Some applications that rely on specific NTFS features might not work readily with ReFS. This poses a compatibility issue for conventional data already possessed by a user. This is why ReFS cannot be called a successor to NTFS right now. You also cannot install apps from the Windows Apps on a ReFS volume.
However, the data integrity and recovery mechanisms in other file systems are not exactly necessary, so there should not be a serious incompatibility issue.
As of now, there are hardly any known tools that can repair a ReFS file system. There are very few third-party tools available that reverse-engineer data, leaving the only solution to be a full format and restore from backup.
The ReFS is a very strong data handling file system with optimization for speed, reliability, and performance. Although, as of October 2017’s Fall Creators update, the ability to create ReFS volumes was removed from Windows 10 except Enterprise and Pro Workstations, so it seems to jeopardize the fact that ReFS file system was a replacement for NTFS. Comment down below if you found this helpful and for further discussions.